import java.util.List;

public class MysingleList implements ILinkedList{
    static class ListNode{
        public int val;
        public ListNode next;
        public ListNode(int val){
            this.val = val;
        }
    }
    public ListNode head;
    public void createList(){
        ListNode node1 = new ListNode(12);
        ListNode node2 = new ListNode(11);

        ListNode node4 = new ListNode(11);
        ListNode node5 = new ListNode(12);
        node1.next=node2;
        node2.next=node4;
        node4.next=node5;
        head = node1;
    }
    public MysingleList() {
        super();
    }

    @Override
    public void addFirst(int data) {
        ListNode node = new ListNode(data);
        node.next = head;
        head = node;
    }

    @Override
    public void addLast(int data) {
        ListNode node = new ListNode(data);
        if(head == null){
            head = node;
            return;
        }
        ListNode cur = head;
        while (cur.next != null){
            cur = cur.next;
        }
        cur.next = node;
    }

    @Override
    public void addIndex(int index, int data) {
        if(index==0){
            addFirst(data);
            return;
        }
        if(index == size()){
            addLast(data);
        }
        ListNode node = new ListNode(data);
        ListNode cur = findIndex(index);
        node.next = cur.next;
        cur.next = node;
    }

    public ListNode findIndex(int index){
        ListNode cur = head;
        int count = 0;
        while(count != index-1){
            cur = cur.next;
            count++;
        }
        return cur;
    }
    @Override
    public boolean contains(int key) {
        ListNode cur = head;
        while(cur != null){
            if(cur.val == key){
                return true;
            }
            cur = cur.next;
        }
        return false;
    }

    @Override
    public void remove(int key) {
        if(head == null){
            System.out.println("链表为空，无法删除！");
            return;
        }
        if(head.val == key){
            head = head.next;
            return;
        }
        ListNode cur = search(key);
        if(cur == null){
            System.out.println("没有要删除的数字："+key);
            return;
        }
        cur.next = cur.next.next;
    }

    private ListNode search(int key){
        ListNode cur = head;
        while(cur.next != null){
            if(cur.next.val == key){
                return cur;
            }
            cur = cur.next;
        }
        return null;
    }
    @Override
    public void removeAllKey(int key) {
        if(head == null){
            return;
        }
        ListNode prev = head;
        ListNode cur = head.next;
        while(cur != null){
            if(cur.val == key){
                prev.next = cur.next;
                cur = cur.next;
            }else {
                prev = cur;
                cur = cur.next;
            }
        }
        if(head.val == key){
            head = head.next;
        }
    }

    @Override
    public int size() {
        int count = 0;
        ListNode cur = head;
        while (cur!=null){
            count++;
            cur = cur.next;
        }
        return count;
    }

    @Override
    public void clear() {
        ListNode cur = head;
        while(cur != null){
            ListNode curN = cur.next;
            cur.next = null;
            cur = curN;
        }
        head = null;
    }

    @Override
    public void display() {
        ListNode cur = head;
        while(cur != null){
            System.out.print(cur.val + " ");
            cur = cur.next;
        }
        System.out.println();
    }
    public ListNode reverseList() {
        if(head == null){
            return null;
        }
        if(head.next == null){
            return head;
        }
        ListNode cur = head.next;
        head.next = null;
        while(cur != null){
            ListNode curN = cur.next;
            cur.next = head;
            head = cur;
            cur = curN;
        }
        return head;
    }
    public boolean chkPalindrome() {
        if(head == null){
            return true;
        }
        ListNode fast = head;
        ListNode slow = head;
        while(fast !=null && fast.next!=null){
            fast = fast.next.next;
            slow = slow.next;
        }
        ListNode cur = slow.next;
        while(cur != null){
            ListNode curN = cur.next;
            cur.next = slow;
            slow = cur;
            cur = curN;
        }
        while(head != slow){
            if(head.val != slow.val){
                return false;
            }
            if(head.next == slow){
                return true;
            }
            head = head.next;
            slow = slow.next;
        }
        return true;
    }
    public boolean hasCycle() {
        ListNode fast = head;
        ListNode slow = head;
        while(fast != null&&fast.next != null){
            fast = fast.next.next;
            slow = slow.next;
            if(fast == slow){
                return true;
            }
        }
        return false;
    }
}
